From nobody Tue Feb 10 05:27:30 2026 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69939157493 for ; Sun, 26 Jan 2025 10:16:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.60.130.6 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737886603; cv=none; b=GweMYjdpu8M/Q1K7g5vi4LTanYM4MUlLACBV0f13QbYzEn+U+/RBI9liTy5HxPb7AOqZbWkifvsFQigW/v8+qOrv05W21zWV9rz2NyJu5CWUJ7EXfS4bNccc5fVore7rNT2YlYoWfCLeMxsaft8dvUlQdu7NB23N2dRw8fLWK2w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737886603; c=relaxed/simple; bh=z0Bk4o0ovuqfLIHT1hnnzGweAJnfYHLhacDV5JwgOLo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TBucCghIDmFhrJoyIFU6oweaQMaimpNBAHImENcPxjZiOPo0UIopcc8M2z8f79zQwBYZf7cQA3UqZOQNQm9aXQtZ95H77QZwP15vDIgfhWohLwIFM5NBPJ1bzsiodTFNf3q6u19JYCgOK672J+9ru1jWVRKe+kA1rc3fzJwsD/Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=S9TPPNqJ; arc=none smtp.client-ip=178.60.130.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="S9TPPNqJ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=yr033ggJ5eKQWklOiqZgHxlCuDTOp6YLDA0oE6TY4PI=; b=S9TPPNqJ3au/zHCuBqQrgqf//K tyE7N7ZUm2bC4nVZ0wsA1nO5pMiQQkPJuHbv5683RVKOdijT1hNaaYsUcVzgX/ond9Y44yDQ5FAz+ 5La9wj5DkA6qnf+2NrU3CBjn3F6ttOWpVwna2EvfirB2+9zWaffYQV1MZi+qMJS/nwkxZc/jduIGT 2tcy98A5uPZ2XUEC6NuS5VSCZBfcaFU8ecGsM+9yvNHhhZw/sy9Iu73NGrzkuEWYW38lFtEovOKIs 6KNipLILE3IfreETssl4ui8yFwRMGZapH2ynlJbLgK8zQQlQCjaGEaf7ZH7P3ilOyzsJOYPDtOKo/ JeeP5FNA==; Received: from [58.29.143.236] (helo=localhost) by fanzine2.igalia.com with utf8esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1tbzgx-002ljG-O4; Sun, 26 Jan 2025 11:16:36 +0100 From: Changwoo Min To: tj@kernel.org, void@manifault.com, arighi@nvidia.com Cc: kernel-dev@igalia.com, linux-kernel@vger.kernel.org, Changwoo Min Subject: [PATCH v2 04/11] sched_ext: Add an event, DISPATCH_LOCAL_DSQ_OFFLINE Date: Sun, 26 Jan 2025 19:16:07 +0900 Message-ID: <20250126101614.232388-5-changwoo@igalia.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250126101614.232388-1-changwoo@igalia.com> References: <20250126101614.232388-1-changwoo@igalia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a core event, DISPATCH_LOCAL_DSQ_OFFLINE, which represents how many times a BPF scheduler tries to dispatch to an offlined local DSQ. __scx_add_event() is used since the caller holds an rq lock, so the preemption has already been disabled. Signed-off-by: Changwoo Min --- kernel/sched/ext.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 727b1f8b623e..38cf7ea6c385 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -1467,6 +1467,12 @@ struct scx_event_stats { * the core scheduler code silently picks a fallback CPU. */ u64 SELECT_CPU_FALLBACK; + + /* + * When dispatching to a local DSQ, the CPU may have gone offline in + * the meantime. In this case, the task is bounced to the global DSQ. + */ + u64 DISPATCH_LOCAL_DSQ_OFFLINE; }; =20 /* @@ -2654,6 +2660,7 @@ static void dispatch_to_local_dsq(struct rq *rq, stru= ct scx_dispatch_q *dst_dsq, if (unlikely(!task_can_run_on_remote_rq(p, dst_rq, true))) { dispatch_enqueue(find_global_dsq(p), p, enq_flags | SCX_ENQ_CLEAR_OPSS); + __scx_add_event(DISPATCH_LOCAL_DSQ_OFFLINE, 1); return; } =20 @@ -5492,6 +5499,7 @@ static void scx_dump_state(struct scx_exit_info *ei, = size_t dump_len) =20 scx_bpf_event_stats(&events, sizeof(events)); scx_dump_event(s, &events, SELECT_CPU_FALLBACK); + scx_dump_event(s, &events, DISPATCH_LOCAL_DSQ_OFFLINE); =20 if (seq_buf_has_overflowed(&s) && dump_len >=3D sizeof(trunc_marker)) memcpy(ei->dump + dump_len - sizeof(trunc_marker), @@ -7821,6 +7829,7 @@ __bpf_kfunc void scx_bpf_event_stats(struct scx_event= _stats *events, for_each_possible_cpu(cpu) { e_cpu =3D per_cpu_ptr(&event_stats_cpu, cpu); scx_agg_event(&e_sys, e_cpu, SELECT_CPU_FALLBACK); + scx_agg_event(&e_sys, e_cpu, DISPATCH_LOCAL_DSQ_OFFLINE); } =20 /* --=20 2.48.1